Factors Associated With Spontaneous Sac Shrinkage in Patients With Persistent Type 2 Endoleaks After EVAR

Purpose: Despite controversy surrounding the management of type 2 endoleaks (T2ELs) after endovascular aortic aneurysm repair (EVAR), the current European guidelines recommend reintervention for T2ELs when the aneurysm expands by >= 10 mm. Meanwhile, sac shrinkage >= 10 mm can be considered low risk for failure even with T2ELs, and the guidelines suggest less frequent follow-up delayed until 5 years after EVAR. This study reviewed patients with persistent T2ELs to identify predictors of spontaneous sac shrinkage (SpS) within 5 years. Methods: A retrospective review of elective EVAR for infrarenal aortic aneurysms between June 2007 and December 2017. Patients with >1 year follow-up and persistent T2ELs, defined as T2ELs confirmed at both the 6 and 12 month follow-up with contrast-enhanced computed tomography (CT), were included. Any reintervention or type 1 or 3 endoleaks within 12 months were excluded. SpS was defined as a >= 10 mm reduction in diameter without any reintervention. Aneurysm enlargement (AnE) was defined as a >= 5 mm increase in diameter. Factors associated with SpS within 5 years were analyzed. The clinical outcomes were reviewed. Results: Among 726 patients, 162 patients had persistent isolated T2ELs. After excluding 21 patients, 141 patients were enrolled. During a median follow-up of 43 months (interquartile range [IQR], 26-60), 28 SpS and 39 AnE were observed, and 31 reinterventions were performed. The cumulative rates of SpS were 14.2%+/- 2.9% and 25.6%+/- 5.1% at 1 and 5 years. Cox regression analysis revealed that the presence of >= 6 patent lumbar arteries had a significant negative correlation with SpS (p=0.036). During further follow-up after SpS, 2 reinterventions for type 1a and 3b endoleaks were required at 49 and 45 months. Conclusions: Patients with fewer patent lumbar arteries were likely to experience SpS within 5 years, even in the presence of persistent T2ELs. Follow-up imaging studies were advisable earlier than 5 years, even after SpS.